This invention relates to a method and to an associated device for automatically removing a toxic substance from a person's blood.
There are presently some 175,000 people in the United States on renal dialysis, up from 100,000 three years ago. Approximately ten percent of the national health budget is allotted to pay for dialysis. Dialysis removes toxins from a patient's blood supply and also removes excess salt and water.
There are currently two principal types of dialysis. Hemodialysis guides blood from a shunt in a person's arm to a filtering machine. The filtered blood is then returned to the patient. In peritoneal dialysis, a fluid is injected into the peritoneal cavity through a thin tube. The peritoneal lining serves as a filter, allowing metabolic toxins from the blood to enter the working fluid in the peritoneal cavity. The fluid is replaced four to six times a day, seven days a week.
Conventional dialysis techniques involve some substantial disadvantages. In hemodialysis, the patient is connected to the filtration machine three continuous hours three times a week. Appointments must be made substantially in advance. The patient's travel opportunities are accordingly severely curtailed. Moreover, hemodialysis is stressing to the heart. Strokes and even death can occur during the procedure. Heparin, a blood thinner or anticlotting agent, must be injected into the patient's blood stream with the possible side effect of bleeding in the brain.
In peritoneal dialysis, peritonitis (infection) is a significant problem. An infection occurs once every sixteen patient months. Also the frequent exchange of the filtrate fluid is cumbersome.
One alternative to conventional dialysis is a kidney transplant. The big problem with such a solution is the necessity of taking medication to prevent rejection of the transplant. Side effects of the drugs include infection, stomach ulcers, weakening of kidney function, and cancer.
It is to be noted that there are many toxins produced by the body which must be metabolized or otherwise eliminated. Many people are born without the ability to eliminate one or more of these toxins. For example, Gaucher's disease entails storage of excessive amounts of glucocerebroside and results eventually in an enlarged liver and spleen and neurological lesions. Nieman-Pick disease involves the excessive storage of phospholipids especially sphingomyelin. Nieman-Pick disease also results in an enlarged liver and spleen, as well as mental retardation and convulsions. In Tay-Sachs disease, there is a build-up of gangliosidoses, which results in blindness and dementia. Death in childhood may be a consequence of any of these three diseases. Other congenital diseases are known which entail the concentration of toxic substances in the body.
U.S. Pat. No. 5,322,503 (application Ser. No. 07/932,368) is directed to a medical method for providing nutrition to a patient. The method of that patent utilizes a container which is implanted intra-abdominally and serves as a reservoir for a total nutrition fluid. The container has an inlet port component disposable in the person's abdominal wall for enabling a periodic refilling of the container. A pump is mounted to the container for periodically pumping an aliquot of a liquid nutrient from the container to a selected vein of the portal vein system.
It has been discovered in conjunction with the present invention that the intra-abdominal reservoir of U.S. Pat. No. 5,318,519 may be useful for treating other kinds of debilitating conditions.